For example, Patent Literature 1 discloses a door mirror device in which a cap and a housing of a door mirror are separately formed, and the cap is attached to the housing in such a manner that the external shape of the cap smoothly continues to the external shape of the housing. Generally, the front side of the housing of the vehicular door mirror is shaped to be more inclined toward the vehicle rear side in portions farther from the vehicle body side in the vehicle width direction.
In the above case, as illustrated in FIGS. 13A and 13B, when the acute angle θA or θB formed between the outer side surface 2 of the vehicle body 1 and the front surface 4 of the housing 3 in plan view in use position of the door mirror is smaller, the air resistance is smaller, and therefore the fuel efficiency and the like are improved. The acute angle θA between the outer side surface 2 of the vehicle body 1 and the front surface 4 of the housing 3 illustrated in FIG. 13A is set smaller than the acute angle θB between the outer side surface 2 and the front surface 4 illustrated in FIG. 13B. (That is, θA<θB.)
In addition, for security reasons, the vehicular door mirror is required to have such a structure that when a collision with an object (obstacle 5) from the vehicle front side occurs, the collision causes the housing 3 to rotate around a rotational axis (not shown) toward the vehicle rear side to a housed position. In FIG. 13B, the points P1 and P2 are the points of collisions between the front surface 4 of the housing 3 and the obstacle 5, and located at a predetermined equal distance D from the outer side surface 2 of the vehicle body 1.